Higher texture resolution no improvement
Higher resolution texture would theoretically improve surface quality for closeups, in the sense that texture might look less blurry.

"Might", because if you are far enough from the mesh surface the difference will probably not be very noticeable and at lower resolutions it becomes harder to see. 
JPEG compression might also wash away some of the detail.

Besides you seem to be using a mix of 1k and 3k images in your node setup, which would further dilute any subtle effect it might have.

My guess is, for your use case and current rendering resolution 1k texture would probably be enough.